Rewrite ${\dfrac{9^{-3}}{9^{-5}}}$ in the form ${9^n}$.
Solution: ${ \dfrac{9^{-3}}{9^{-5}} = 9^{-3-(-5)}} $ ${ \hphantom{\dfrac{9^{-3}}{9^{-5}}} = 9^{2}} $